1. Field of the Invention
The present invention relates to a stereo sounding method, a stereo sounding system, and a musical tone generation control system.
2. Description of the Related Art
In general, a stereo speaker system which is now widely used is comprised of right and left speakers arranged at a predetermined interval in front of a listener.
The listener listens to stereo sounds and others output from the pair of speakers from a position where he/she sees the pair of speakers ahead on the right and left. In this speaker system, however, the listener cannot listen to desirable sounds such as stereo sounds if he/she does not lie at a position where he/she sees the pair of spears ahead on the right and left as above. In other words, if the listener moves to become close to one of the speakers, or if the listener lies at a position where the right and left speakers are overlapped in the same direction, the listener cannot listen to desirable sounds such as stereo sounds. Also, if a large number of listeners lie around the speaker system, only part of the listeners can listen to desirable sounds such as stereo sounds.
To address the above problems, speaker systems illustrated in FIGS. 9 and 10 have been proposed, for example.
The speaker system in FIG. 9 is comprised of speakers L1 to L9 which output an L-channel output from a stereo sound source, not shown, and speakers R1 to R8 which output an R-channel output from the stereo sound source. These speakers L1 to L9 and R1 to R8 are alternately arranged on the circumference of the generally cylindrical housing. The speakers R1 to R8 and L1 to L8 are arranged such that the angle formed by a straight line connecting the center of the circle, i.e. the diametrical center of the housing, to the center of each speaker and a normal line extending vertically from the center of each speaker is kept at an angle θ (θ=57°), and the stereo sound radiation angle formed by speakers whose radiation surfaces are adjacent in opposed relation (for example, the speakers R4 and L4) is kept at 90°.
This speaker system can provide realistic sounds such as stereo sounds for a large number of listeners (refer to Japanese Laid-Open Patent Publication (Kokai) No. 2001-211495 (page 2, and FIGS. 1 and 2))
The speaker system in FIG. 10 is constructed such that a plurality of speakers are arranged in a radial array. A sound output signal in a left channel and a sound output signal in a right channel are supplied to each speaker, and a sound corresponding to each signal is output from each speaker. According to this speaker system, it is possible to acquire a correct sound image localization in a predetermined direction. Also, it is possible to listen to a reproduced sound even in e.g. a direction opposite to a predetermined direction (in this case, however, the sound image localization is opposite to the above correct sound image localization). As a result, a listener can feel as if he/she were listening to sounds output from the back surface of a sound source (refer to Japanese Laid-Open Patent Publication (Kokai) No. H09-271095 (pages 2 and 3, and FIGS. 1 and 2).
By the way, the above described speaker systems in FIGS. 9 and 10 are configured to reproduce sounds from a single sound source. Further, in the speaker system in FIG. 10, it is not assumed that it reproduces sounds from a plurality of sound sources. Thus, if it is necessary to reproduce sounds from a plurality of sound sources as in performance of an ensemble of electronic instruments, sounds from the sound sources are mixed before they are supplied to speakers, and the resulting mixed sound is reproduced by the speaker system.
A speaker system in FIG. 11 is an improvement of the speaker system in FIG. 10, which is capable of reproducing sounds from a plurality of sound sources.
This speaker system is similar to the speaker system in FIG. 10 in that speakers are arranged in a substantially circular array inside a large number of listeners, but is different from the speaker system in FIG. 10 in that sounds such as stereo sounds can be provided for the listeners. This speaker system is comprised of first to tenth speakers SP1 to SP10 which are arranged in respective pairs and in respective directions. The speakers SP1 to SP10 are connected to respective corresponding stereo sound sources; the first speaker SP1 and the second speaker SP2 are connected to an L-channel and an R-channel, respectively, of a first stereo sound source, the third speaker SP3 and the fourth speaker SP4 are connected to an L-channel and an R-channel, respectively, of a second stereo sound source, and similarly, each of the fifth to tenth speakers SP5 to SP10 is connected to an L-channel or R channel of a corresponding stereo sound source.
According to the speaker system in FIG. 11, the speakers of each of the pairs arranged in various directions are connected to respective L- and R-channels of a corresponding stereo sound source, and therefore it is possible to provide realistic sounds such as stereo sounds for a large number of listeners.
The speaker system in FIG. 11, however, has the problem that the speakers have to be arranged in pairs and in respective different directions, and hence a large number of speakers are required, which causes a rise in production cost.
Also, the speaker system in FIG. 11 has the problem that a large number of speakers have to be accommodated in a housing, and hence the housing must be large in size and is therefore inconvenient for carrying.